1. Field of the Invention
The present invention relates to a method for forming a terminal metal used in a wiring harness and a terminal metal formed by the method.
2. Related Art
Various types of electronic appliances are installed on an automobile as a mobile body. Wiring harnesses are laid out on the automobile for supplying power and transmitting control signals to the electronic appliances so installed. The wiring harnesses each include a plurality of electric wires and a plurality of connectors. The electric wires are so-called covered wires each made up of a conductive core wire and an insulating coating portion which covers the core wire.
The connectors each include a pair of insulating connector housings which are fitted together and conductive terminal metals which are housed in those housings. The terminal metals each include a wire connection part which is attached to an end portion of the electric wire so as to make an electric connection with the core wire at one end and at the other end thereof an electric contact part which is brought into contact with a mating terminal metal. The wiring harness transmits control signals and the like to the electronic appliance when the corresponding connector housings of the connector therefor are connected together.
In a wiring harness production process, terminal metals which are different in the shape of wire connection parts are selected to be used according to connection treatment methods and types of electric wires, and there exist, as these terminal metals, for example, a terminal metal having a clamp portion where a core wire of an electric wire which is exposed by stripping off a coating portion thereof is clamped (hereinafter, referred to a clamp terminal as shown in JP-A-2004-193073), a terminal metal having a crimp portion where a coating portion of an electric wire is cut for contact with a core wire therein (hereinafter, referred to as a crimp terminal as shown in JP-A-2003-217698), and a terminal metal having a piercing portion where a flat cable is pierced for contact with a core wire therein (hereinafter, referred to as a piercing contact as shown in JP-A-2003-115340).
Note that a connection using the clamp terminal is suitable for connection of a power supply cable which requires a high connecting reliability, and a connection using the crimp terminal is suitable for automation of a production process. In addition, a connection using the piercing contact is suitable for connection of a flat cable and has an advantage that the wiring space can be reduced.
Furthermore, in each of these terminal metals, there exist a terminal metal having a male electric contact part (hereinafter, referred to as a male contact portion as shown in JP-A-8-162191) and a terminal metal having a female electric contact part (hereinafter, referred to as a female contact portion as shown JP-A-2-2-63961). A male contact portion of one terminal metal is accommodated in a female contact portion of the other terminal metal, whereby an electric connection is established therebetween. In addition, in order to maintain a fitting compatibility, the male contact portion and the female contact portion are formed into the same shapes even in terminal metals which differ in type of wire connection parts.
The conventional terminal metals are formed by bending sheets metal obtained by stamping conductive sheets metal with dies prepared under product numbers allocated for the respective terminal metals. The wire connection part and the electric contact part are integrally formed. Namely, since parts of the same shape are formed with different dies, there are caused problems that variation in performance is generated among the parts due to manufacturing tolerance of the shape, and that there are formed wasteful dies for forming parts of the same shape.